LISTENER=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=IPC)(KEY=LISTENER)))) # line added by Agent
LISTENER_SCAN1=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=IPC)(KEY=LISTENER_SCAN1)))) # line added by Agent
ENABLE_GLOBAL_DYNAMIC_ENDPOINT_LISTENER_SCAN1=ON # line added by Agent
ENABLE_GLOBAL_DYNAMIC_ENDPOINT_LISTENER=ON # line added by Agent

problem:
1. From client 11g r2 I can connect both instance by above tnsnames.ora.
for testing node failover:
when I reboot node1 connected session from node1 is not shifted to node2 ( node2 is up).
similarly when node2 is reboot node2 connected session is not shifted to surviving node node1. instead message show oracle not connected.

If you do not have DNS, how do you expect your client to find your scan IP address? that would require it to be in every client you expect to connect to the server. Now, the kicker, in my testing, it appears that you can do the install with /etc/hosts, but in real operation the mechanism used by scan uses gethostbyname - which is DNS only and does not look at /etc/hosts - regardless of your setting for resolv.conf. Not sure about how it works on HP-UX.

if you do not properly configure your environment, you can expect a LOT of unexplained problems in the future.

What I understand is SCAN is not present in DNS, whereas it's a mandate for SCAN IPs (3 IPs registered against same DNS-entry, which get resolved in a round robin fashion when the DNS-entry is pinged). Believe me, you can play with local hostname resolution and escape pre-req checks on installer screens, or with environment variables (like IGNORE_PREADDNODE_CHECKS=Y) whenever you come across a DNS resolution failure - but, you will not find all the blessings of SCAN.
You can always try avoiding the necessity of SCAN with "/etc/hosts" (or its Windows equivalent):

#Scan
xxx.xxx.0.5 rac-scan
xxx.xxx.0.6 rac-scan
xxx.xxx.0.7 rac-scan

I would recommend you to reach out your network admin and get such SCAN setup done for you in DNS.

In case you are getting an ORA-03113 with the failover, considering the non-availability of DNS entries for SCAN, there might be a need to configure TAF like we used to do earlier. That is...